Long Slit



The Long-Slit Levitator Experiment

A colleague of mine doubts that Radial Momentum explains lift, and claims it is a Bernoulli Principle effect. To prove his case, he proposes I build a long-slit orifice device that would preclude the development of Radial Momentum. If such a configuration could demonstrate lift, it would indicate independence of lift from Radial Momentum and disprove my theory once and for all. Rather than prove his case, the device shows little ability to lift a card, further advancing the case for Radial Momentum. In honor of his contribution, I used his business card in the demonstration.



The Long-Slit Levitator

According to classical Bernoulli Principle application, a business card should adhere to a long-slit levitator. According to the theory of Radial Momentum, as long as it stays rigid and parallel to the surface, it should blow off. The card lays flat on the bed, against the slit. The head and foot boards prevent radial flow at the ends of the business card.



Levitator showing long-slit orifice.



Levitator with card in position. In operation, I turn the device upside-down and apply air through the fitting, so as to test adherence of the card. I fabricated the device from acrylic plastic.


Test Results

The levitator does not lift anything rigid brought up parallel to its surface, like plastic disks or even a card made of Styrofoam. If there is any lift at all, it is substantially less than that observed with devices that allow Radial Momentum. Furthermore, lift only obtains when the test object is brought up at a slight angle to the surface so as to allow external coning, a radial expansion artifact. Similarly, the device also suspends a bowed business card brought up lengthwise underneath the bed. The device does not lift a business card brought up crosswise underneath the bed. These findings indicate that to the extent Radial Momentum is precluded, lift is also precluded. The popular interpretation of Bernoulli's Principle, that high velocity causes low pressure, does not explain lift.


External Coning

Unless the card is kept parallel with the face of the levitator, a coning region that supports Radial Momentum may develop between the card and the levitator.